Puller for timing gears of internal combustion engines



Nov. 18, 1958 H. R. GRUNDER ETAL 2,850,407

FULLER FOR TIMING GEARS OF INTERNAL COMBUSTION ENGINES Filed Sept. 25, 1953 Illi H mgsmogs.

0/ 0 r40? 2/ W/W/am .W/r/fekead United States Patent PULLERFOR TIMING GEARS OF INTERNAL COMBUSTION ENGINES Harold R. Grunder and William R. Whitehead, Wichita, Kans.

Application September 25, 1953, Serial No. 382,444

1 Claim. (Cl. 29-258) tion to provide a timing gear puller having parts engageable with'the gear and the cam shaft whenthe timing gear is to be pulled and accessory parts engageable with the gear and a part of the engine itselfwhe n the said timing gear is to be replaced upon the cam shaft.

Another important object of this invention is to provide a tool of the aforementioned character that includes a plate especially made to partially embrace the cam shaft and engage the timing gear when the tool is used as a puller, the remaining essential components of the puller including a cross head having a thrust screw bearing against one end of the cam shaft, together with a number of bolts adapted to pass through the timing gear and engage with the plate.

A still further object of this invention includes the way in which bolts forming a part of the tool engage with a thrust plate on the engine block when the tool is used to replace the timing gear, together with the way in which an accessary plate is provided for rotatably receiving the thrust screw and bearing against the gear to be replaced on the cam shaft.

Other objects include the manner in which the shaft embracing plate is provided with adjustable means for aligning the same; the manner of providing an end segment to receive the thrust of the cam shaft when the gear is placed thereon, together with many'additional more minor objects, all of which will be made clear or become apparent as the following specification progresses.

In the drawing:

Figure 1 is an end elevational view of a puller for timing gears of internal combustion engines showing the same operably mounted ready for pulling the timing gear from the cam shaft of the engine.

Fig. 2 is a cross-sectional view taken on line II-Il of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a fragmentary, cross-sectional view taken on line III-III of Fig. 1.

Fig. 4 is a cross-sectional view similar to Fig. 2, illustrating the puller hereof with the necessary accessory parts for adapting the same to replacement of the timing gear upon the cam shaft; and

Fig. 5 is a detailed, cross-sectional view taken on line V-V of Fig. 4.

It is well understood by mechanics generally that a considerable amount of repair and replacement work in internal combustion engines necessitates pulling and replacement of the timing gear, particularly when the cam shaft and the cams thereon are to be repaired or replaced. The timing gear is mounted on one end of the cam shaft with an extremely tight press fit and the task of removal and replacement is time-consuming and normally rather difficult. As will hereinafter appear,

the tool forming the subject matter hereof renders such removal and replacement of the timing gear relatively simple and quickly accomplished. V M

The tool and its component parts when used fonremoving timing gears 10 of internal combustion engines, is shown in Figs. 1 to 3 inclusive of the drawing. Figure 2 clearly illustrates the way in which the gear 10 is normally mounted on one end of a cam shaft 12 forming a part of an internal combustion engine. Shaft 12 is provided with end bearings 14 and 16 mounted within bushings 18 and 20 respectively of engine block 22. .An engine thrust plate 24 rigidly secured to the block 22 in surrounding relationship to the bearings 14, is conventionally provided with a number of internally threaded openings 26.

The timing gear 10 has a hub 28 that is fitted tightly over one end of the shaft 12 adjacent the bearing 14 as is clear in Figs. 2 and 3. I v

The tool as shown in Figs. 1 to 3 inclusive, includes an elongated cross head 30 provided with a centrally disposed, internally threaded bore 32 and a pair of holes 34 equally spaced from the bore 32. The bore 32 is adapted to receive an elongated thrust screw 36 having a tool-receiving head 38 on one end thereof, and a pivot pin insert 40 removably mounted on its opposite end. A spring-loaded detent 42 'releasably holds the pin 40 attached to the screw 36. g O

The holes 34 are adapted to receive elongated bolts 44 that extend through clearance openings 46 that are formed in the gear 10. A substantially semi-circular plate 48 has a pair of diametrically opposed, internally threaded openings 50 therein for receiving the,b0lts 44 and a slot 52 for clearing the bearing 14 on shaft 12 as shown in Figs. 1, 2 and 3. Plate 48 is disposed between the gear 10 and plate 24 when the tool is used for pulling the gear 10 from the shaft 12 and a small adjustable, L-shaped bracket 54 on the plate 48, aids in aligning the openings 50 with the openings 46. It is noted that bracket 54 extends into overlying engagement with the gear 10 when the plate 48 is properly aligned to receive the bolts 44.

When the tool is mounted as shown in Figs. 1 to 3 inclusive, it is but necessary to apply a suitable wrench to the head 38 of screw 36 and to turn the screw 36 in the proper direction for exerting a pull upon the cross head 30 and therefore, upon the plate 48 through the bolts 44. By virtue of the fact that the pivot pin 40 isseated within a cavity 56 formed in the proximal end of shaft 12, gear 10 will be forced from the shaft 12 in the direction of arrows 58 in Fig. 2, all without damaging either the gear 10 or the shaft 12 or shifting the latter with respect to the block 22 within which it is mounted. After removal of the timing gear 10, the shaft 12 and/ or cams 60 thereon may be removed or repaired in the usual manner.

The plate 48 and bracket 54 are not utilized when the tool is employed for the purpose of replacing the timing gear 10 upon the shaft 12 in the manner shown by Fig. 4 of the drawing. Screw 36 in cross head 30 is utilized, the holes 34 in cross head 30 receive bolts 44, and the same are adapted to extend through the openings 46 into threaded engagement with the internally threaded openings 26 of the thrust plate 24.

A circular plate 102 is utilized to rotatably receive the pivot pin 40 by means of a complementally-shaped cavity 104 in one face of plate 102. A cavity 106 in the opposite face of the plate 102 receives the hub 28 of gear 10.

It is seen that as torque is applied in one direction to the screw 36, bolts 44 attached to the plate 24, will hold the cross head 30 against outward movement away from the plate 24 and that consequently, the force applied 3 to the plate 102 will be imparted to the gear 10 and cause the hub 28 thereof to slip over the proximal end of shaft 12.

In order to avoid any damage to the shaft 12 and to prevent the same from inward movement as gear 10 is forced thereon, an arcuate thrust segment 1% is provided as shown in Figs. 4 and 5. Segment 188 has an arcuate groove 110 therein for receiving the bearing 16 and is adapted as shown in Fig. 4 of the drawing for fitting between the bearing 16 and block 22 during the time that gear 10 is being mounted on the shaft 12. A pair of diametrically opposed, spring-loaded detents 112 yieldably hold the thrust segment 108 in place.

Inasmuch as the cross head 30 remains stationary with respect to the block 22 during use of the tool as a means for replacing the gear 10, cross head 36 may well be adapted in any suitable manner for attachment to the block 22 and/or any other part of the engine. To this end, it is but necessary to merely extend the cross head at one end thereof for attachment to the crank shaft pinion (not shown) that normally meshes with the gear 10 and to extend the opposite end of the cross head 30 for attachment to the engine block 22 such as through use of bolts in the screw holes of the fuel pump of the internal combustion engine.

Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is:

In apparatus for pulling the timing gear from the cam shaft of an internal combustion engine, a tool comprising a cross-head having a central, internally threaded bore and a pair of holes spaced equally from the bore;

a thrust screw threaded in said bore and engageable with the cam shaft; a bolt in each hole respectively, said gear having clearance openings therein for passage of said bolts; a generally inverted U-shaped, circularly segmental, gear-engaging plate having threaded openings therein disposed upon a horizontal diameter thereof for receiving said bolts, said plate having a central slot extending upwardly from the bottom, chord edge thereof for clearing the cam shaft, the bolts having heads thereon engageable with the cross-head for limiting the extent of movement thereof when the screw is turned whereby, upon further turning of the screw, the plate engages the gear to pull the same from the shaft; and an L-shaped bracket having one leg thereof attached adjustably to the plate at the top of the latter and on a central axis of the slot and the other leg thereof extending across the plate in a direction toward the cross-head, said other leg being engageable with the top of the gear for aligning the openings of the plate with the openings of the gear during installation of the apparatus.

References Cited in the file of this patent UNITED STATES PATENTS 1,305,322 Towler June 3, 1919 1,383,382 Brockway July 5, 1921 1,559,885 Kelley Nov. 3, 1925 2,298,408 Moyer Oct. 13, 1942 FOREIGN PATENTS 829,129 Germany Jan. 24, 1952 

